The present invention relates to the field of ophthalmology. In particular, the present invention relates to diagnostics useful in eye examinations.
During the course of a typical eye examination, the patient's pupils are dilated so that the posterior tissues of the eye can be examined. In general, alpha-1 adrenergic agonists, such as phenylephrine, are used to dilate the pupil (induce mydriasis); however, residual mydriasis after the eye examination may interfere with patient functioning and is undesirable. In addition, the drug-induced mydriasis may precipitate an attack of angle closure glaucoma in susceptible individuals.
The mydriatic action of phenylephrine and other alpha-1 agonists may be competitively inhibited or reversed by using alpha-1 adrenergic antagonists. The most widely used agent to date has been dapiprazole; however, there are several disadvantages to using dapiprazole. Due to its instability in solution, the dapiprazole product is supplied in three parts (drug and excipient ingredients) which require reconstitution by a qualified individual prior to use. This reconstituted product has a very limited shelf life (on the average 21 days). The product causes discomfort in the eye and has been known to cause side effects, such as burning, lid edema, chemosis, browache, headaches, and itching, in a large number of patients. Moreover, multiple instillations must be administered in order to achieve the desired effect.